Compaq EK-SMCPO-UG. C01 manual Units created from storagesets, partitions, and disk drives

2-4RAID Array 3000 Pedestal Storage Subsystem Hardware User’s Guide

From the pedestal’s perspective, the controller receives the I/O requests from the host and directs them to the devices in the pedestal. Since the controller processes all the I/O requests, it eliminates the host-based processing that is typically associated with reading and writing data to multiple storage devices.

The controller does much more than simply manage I/O requests: it provides the ability to combine several ordinary disk drives into a single, high- performance storage unit called a storageset. Storagesets are implementations of RAID technology, also known as a Redundant Array of Independent Disks. Every storageset shares one important feature: whether it uses two disk drives or 14, each storageset looks like a single storage unit to the host.

You create storage units by combining disk drives into storagesets such as stripesets, RAIDsets, and mirrorsets, or by presenting them to the host as single-disk units (Figure 2–2).

Figure 2-2. Units created from storagesets, partitions, and disk drives